ORIGINAL: KC36330
I've got the Modellbau servo pacakge in mine, all analog servos, the only exception is i had one bad servo so used a Futaba 3010 on steering, JR R1221 receiver. P-60SE gives me a 10 min in flight on the 80oz of fuel and i've only sucked her dry and flamed out a few times but it's quiet low when i land most of the time.
I'm newly waivered... so my timer is set short. (don't want to try a dead stick yet) I could probably go out to a 7 minute flight since I land with about 15 ~ 20 Oz left in the tank. BUT... your longer flights would explain the power difference.
Regardless, I think you are safe for 4 or 5 flights between charges.